Hagen is the 41st-largest city in Germany, located in the federal state of North Rhine-Westphalia. It is located on the south eastern edge of the Ruhr area, 15 km south of Dortmund, where the rivers Lenne and Volme (met by the river Ennepe) meet the river Ruhr. As of 31 December 2010 the population was 188,529. The city is home to the FernUniversität Hagen, which is the only state funded distance education university in Germany. Counting more than 67,000 students (March 2010), it is the largest university in Germany.

Hägen is a village and a former municipality in the district of Dithmarschen, in Schleswig-Holstein, Germany. Since 1 January 2009, it is part of the municipality Süderheistedt.